Development of a rolling finishing system to deliver net shape components from titanium structural extruded shapes

摘要

The high cost of manufacturing with titanium is the predominant barrier to wider adoption of the material into new applications, despite attractive material properties. The manufacture of long structural shaped product for framing applications has largely been relegated to lower cost alternative materials. Producing comparable structures from titanium requires different manufacturing processes due to the material's response during thermo-mechanical deformation. Traditional bulk rolling of titanium into shapes has proven enigmatic due to the occurrence of shear banding and cracking from significant levels of non-uniform deformation and sensitivities to temperature non-uniformities. The current manufacturing method of long structural shapes is through an extrusion process. The inability to deliver thickness and surface quality dictate the machining of all surfaces to deliver complete components. This machining operation is the most significant cost driver for the components due to material loss and difficulty of machining titanium. This experimental effort proved a novel system, for the processing of titanium, that couples the two processes to deliver capabilities that neither could independently. The coupling of these two systems enabled mitigations of shortcomings of the individual systems. Thicknesses and surface quality aligned with a finished or net shape component were achieved without requiring a machining operation. In the experimental effort, a series of specimen were processed under varying temperature and deformation rates during rolling. These process variables are correlated to resulting material quality and to complexities associated with the coupling of the rolling and extrusion operations. (C) 2018 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.